摘要
Abstract
Objective To observe the effect and mechanism of Astragalus polysaccharides(APS)mediated TGF-β1/Smad signaling pathway in asthma airway inflammation.Methods Forty female BALB/c mice were allo-cated randomly into five groups,eight animals per group:Normal Saline(NS),Asthma group(AS),and low dosage of APS(AL),high-dose APS(AH),and dexamethasone groups(Dex).The AS,AL,AH,and Dex groups were sensitized with a 10％ovalbumin(OVA)solution via intraperitoneal injection,followed by multiple subcutaneous injections and successive nebulization,once a day,30 minutes each.In AL,AH and Dex groups,APS 200,400 mg/kg and dexamethasone 2 mg/kg were injected intraperitoneally 30 minutes before aerosol chal-lenge.Mice were anaesthetized and then sacrificed by bleeding at the end of experiment,after which lung tissue and bronchoalveolar lavage fluid(BALF)were collected.BALF was used for total and differential cell counts,while lung tissue was processed for histological examination with HE and Masson's trichrome staining to assess lung inflammation and collagen deposition.The levels of inflammatory cytokines(IL-4,IL-5,IL-13)and growth factor TGF-β1 in the BALF were determined using ELISA assays.To assess the expression of TGF-β1 and α-smooth muscle actin(α-SMA),immunohistochemistry was performed.The mRNA levels of TGF-β1 and Smad3 in the lung tissue were quantified using qPCR.Western blotting was used to measure levels of proteins linked to the TGF-β1/Smad3 signaling pathway.Results APS treatment improved lung pathological damage,reduced BALF cell counts,and levels of inflammatory factors(IL-4,IL-5,IL-13,TGF-β1)as well as collagen fiber deposition around the airways,with the AH group showing better results than the AL group(P＜0.05).Howev-er,the effect of APS in improving airway inflammation in asthmatic mice was not as effective as the Dex group.Immunohistochemistry,Western blotting,and real-time PCR suggest that APS treatment in asthmatic mice can reduce the expression of TGF-β1 and α-SMA in lung tissue(P＜0.05),with the high-dose group being superior to the low-dose group(P＜0.05).Conclusion APS can reduce airway inflammation and improve airway remod-eling in asthmatic mice,which may be partly through regulating TGF-β1/Smad signaling pathway.关键词
支气管哮喘/黄芪多糖/气道炎症/转化生长因子Key words
bronchial Asthma/Astragalus polysaccharide/airway inflammation/transforming growth factor-β分类
临床医学
